fix(btree): index collision (with description)

add checking index collision when finding values
remove additional inserting operations on index collision situation

headers/btree.h

@@ -38,7 +38,7 @@ void move_kv(struct BTreeNode *node, const uint32_t at, const uint32_t to);
 uint32_t find_node_of_index(struct BTreeNode **result, struct BTreeNode *search, const uint64_t index);
 
 struct BTreeValue *insert_value_to_btree(struct BTree *tree, const uint64_t index, void *data);
-struct BTreeValue *find_value_from_btree(struct BTree *tree, const uint64_t index);
+struct BTreeValue *find_value_from_btree(struct BTree *tree, const uint64_t index, void *arg, bool (*check)(void *value, void *arg));
 bool delete_value_from_btree(struct BTree *tree, const uint64_t index, void (*free_value)(void *value));
 
 void free_btree(struct BTree *tree, void (*free_value)(void *value));

headers/database.h

@@ -31,6 +31,7 @@ void save_data(const uint64_t server_age);
 bool bg_save(uint64_t server_age);
 
 void set_kv(struct KVPair *kv, const string_t key, void *value, const enum TellyTypes type);
+bool check_correct_kv(struct KVPair *kv, char *key);
 void free_kv(struct KVPair *kv);
 /* /DATABASE */
 

src/btree/delete.c

@@ -241,6 +241,7 @@ static void delete_from_leaf(struct BTree *tree, struct BTreeNode *node, const u
   }
 }
 
+// TODO: deleting correct values for collised indexes on inserting values to b-tree
 bool delete_value_from_btree(struct BTree *tree, const uint64_t index, void (*free_value)(void *value)) {
   struct BTreeNode *node;
   const uint32_t target_at = find_node_of_index(&node, tree->root, index);

src/btree/find.c

@@ -2,27 +2,49 @@
 
 #include <stdint.h>
 #include <string.h>
+#include <stdbool.h>
 
-static struct BTreeValue *find_value_from_node(struct BTreeNode *node, const uint64_t index) {
+static struct BTreeValue *find_value_from_node(struct BTreeNode *node, const uint64_t index, void *arg, bool (*check)(void *value, void *arg)) {
   if (node->children) {
-    for (uint32_t i = 0; i < node->size; ++i) {
-      struct BTreeValue *value = node->data[i];
-      if (index < value->index) return find_value_from_node(node->children[i], index);
-      else if (index == value->index) return value;
+    if (check) {
+      for (uint32_t i = 0; i < node->size; ++i) {
+        struct BTreeValue *value = node->data[i];
+        if (index < value->index) return find_value_from_node(node->children[i], index, arg, check);
+        else if (index == value->index) {
+          if (check(value->data, arg)) return value;
+          else {
+            struct BTreeValue *left = find_value_from_node(node->children[i], index, arg, check);
+            if (left) return left;
+          }
+        }
+      }
+    } else {
+      for (uint32_t i = 0; i < node->size; ++i) {
+        struct BTreeValue *value = node->data[i];
+        if (index < value->index) return find_value_from_node(node->children[i], index, arg, check);
+        else if (index == value->index) return value;
+      }
     }
 
-    return find_value_from_node(node->children[node->size], index);
+    return find_value_from_node(node->children[node->size], index, arg, check);
   } else {
-    for (uint32_t i = 0; i < node->size; ++i) {
-      struct BTreeValue *value = node->data[i];
-      if (index == value->index) return value;
+    if (check) {
+      for (uint32_t i = 0; i < node->size; ++i) {
+        struct BTreeValue *value = node->data[i];
+        if (index == value->index && check(value->data, arg)) return value;
+      }
+    } else {
+      for (uint32_t i = 0; i < node->size; ++i) {
+        struct BTreeValue *value = node->data[i];
+        if (index == value->index) return value;
+      }
     }
   }
 
   return NULL;
 }
 
-struct BTreeValue *find_value_from_btree(struct BTree *tree, const uint64_t index) {
-  if (tree->root) return find_value_from_node(tree->root, index);
+struct BTreeValue *find_value_from_btree(struct BTree *tree, const uint64_t index, void *arg, bool (*check)(void *value, void *arg)) {
+  if (tree->root) return find_value_from_node(tree->root, index, arg, check);
   else return NULL;
 }

src/btree/insert.c

@@ -6,7 +6,6 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-// TODO: invalid inserting on multiple same value indexes
 static struct BTreeValue *insert_value_to_node(struct BTree *tree, struct BTreeNode *node, struct BTreeValue *value, const uint32_t value_at) {
   tree->size += 1;
   node->size += 1;
@@ -186,17 +185,10 @@ struct BTreeValue *insert_value_to_btree(struct BTree *tree, uint64_t index, voi
 
     return value;
   } else {
-    while (true) {
-      struct BTreeNode *node;
-      const uint32_t value_at = find_node_of_index(&node, tree->root, index);
-
-      if (value_at < node->size && node->data[value_at]->index == index) {
-        index += 1;
-        continue;
-      } else {
-        return insert_value_to_node(tree, node, value, value_at);
-      }
-    }
+    struct BTreeNode *node;
+    const uint32_t value_at = find_node_of_index(&node, tree->root, index);
+
+    return insert_value_to_node(tree, node, value, value_at);
   }
 
   return NULL;

src/commands/kv/rename.c

@@ -16,7 +16,7 @@ static void run(struct Client *client, commanddata_t *command, struct Password *
     const string_t search = command->args[0];
     const uint64_t index = hash(search.value, search.len);
 
-    struct BTreeValue *value = find_value_from_btree(get_cache(), index);
+    struct BTreeValue *value = find_value_from_btree(get_cache(), index, (char *) search.value, (bool (*)(void *, void *)) check_correct_kv);
 
     if (value) {
       struct KVPair *kv = value->data;

src/database/cache.c

@@ -17,17 +17,10 @@ struct BTree *get_cache() {
 
 struct KVPair *get_kv_from_cache(const char *key, const size_t length) {
   uint64_t index = hash((char *) key, length);
+  struct BTreeValue *value = find_value_from_btree(cache, index, (char *) key, (bool (*)(void *, void *)) check_correct_kv);
 
-  while (true) {
-    struct BTreeValue *value = find_value_from_btree(cache, index);
-
-    if (value) {
-      struct KVPair *kv = value->data;
-
-      if (strncmp(kv->key.value, key, length) == 0) return kv;
-      else index += 1;
-    } else return NULL;
-  }
+  if (value) return value->data;
+  else return NULL;
 }
 
 bool delete_kv_from_cache(const char *key, const size_t length) {

src/database/kv.c

@@ -43,3 +43,7 @@ void free_kv(struct KVPair *kv) {
   free(kv->key.value);
   free(kv);
 }
+
+bool check_correct_kv(struct KVPair *kv, char *key) {
+  return streq(kv->key.value, key);
+}